Hoisting mechanism



Patented Aug. 5, 1924s UITED `s'mrias Application filed May 31,

To all whom tmag/ concern:

Be it known thatlLJoHN A. MORRISON, a citizen of the United States,residing at Mansfield, in the county of Richland and State of Ohio,.haveinvented certain newV and useful Improvements in Hoisting Mechanism, ofwhichthe following is a'specification. i Y

This invention relates to hoisting mechanism andthe objectsof theimprovement i are toprovide mechanism of this class in which the load iscounterbalaneed, thus re# quiring very little power to raise aconsiderable weight.

rlphe above and 'other bbjects may be at tainedv by p'roviding'a framein vwhich a lifting bar is vertically slidable and arranged to supportthe load,4 a vertically, slidable block beingmounted.adjacent to thelifting bar and carrying a' pinion meshing with a rack upon the liftingbar, Aa flexible member being connected to the lifting bar and passedupward over a pulley and downward to a point of connection with theslidable block, means being provided for normally preventing rotation ofthe pinion and for rotating the same in either direction to raise orlower the lifting bar.

' Anembodiment of the inventio-n thus set forth in general yterms isillustrated inthe accompanying drawing, inwhich-- Figure 1 is a sideelevation of a hoisting mechanism embodying the invention;

Fig. 2, an edge elevation of the same;

Fig. 3, a side elevation of the slidable block; and

Fig. 4, a plan view of the same.

Similar numerals refer to similar parts throughout the drawing.

The mechanism is mounted ina frame comp-rising the base 1 and thespaced, parallel upright guides 2 and 3. preferably connected at theirupper ends as at 4 for the purpose of strengthening the same.`

The lifting bar 5 is slidably mounted inthe guide-way 2 and providedwith a head 6' at its upper end to receive the load, rack teeth 7 beingformed upon the inner face of the bar.

A channel shaped block v 8 is slidably mounted in the guide-way 3 andthe shaft 9 is journaled transversely therethrough, a pinion 10 beingxed upon the shaft with-y in the channel portion of the block and PATENT.oFFieEg JOHN A. MOBRISQN, QFVLANSFIELD, GEIQ,y

1923. serial No, 642,463

meshing with the rack teeth 7 of the lifting bar.

A wormV gear 11 is fixed upon each outer end of the shaft 9. ,oA spacedpair o-f ears 12 extends outward from each side of the block 8 formingbearings -for the worm shafts 13, the worms 14 thereon meshing with theworm wheel-s 11, ball bearings 15 preferably being provided upon saidworms.

The outer endof each lworm shafthis provided with a flat sided shank 16to v'receive the socket of -a suitable tool fory rotating the same, andpinions 17k are fixed upon the worm shafts andmesh with anidler 18j'o-urnaled as at 19 upon the frame.

A sprocket chain or other flexible mem' ber-19a is connectedtofeach'side of the block 8 at the ,upper end Y thereof, preferablythrough the boss 20 and passes upward over a sprocket wheel or pulley 21and downward to an ear 22 fixed upon the outer side of the lifting bar 5and extended through the vertical slot 23in the frame.

Thus as the load is placed upon the upper end of the lifting bar, thesame will be equally distributed between the lifting bar and the block 8as a portion of the load is transmitted through the chains 19a over thepulley 21 to the block 8. Y

The kworms 14 meshing with the worm wheels 11 normally prevent rotationof the shaft 9, thus holding the parts against move- -ment by theplacing of the load upon the through the same the shaft 9 and pinion 10to raise or lower the 'lifting bar, moving the block 8 in the oppositedirection, maintaining the flexible rmembers 19a taut, while under load.l n K As the load is thus -balanced between they lifting bar andtheslidable block 8, it will vbe seen that the load'itself assists greatlylin Yraising the lifting bar, greatly-reducing the amount of powernecessary to 'rotate the worms 14 to raise the load.

I claim 1. Athoisting mechanism including a ver tically movable rackbar, a vertieallymovable block, `a pinion carried by the block meshingwith the rack bar,' a pulley,"a flexible member extended upward over thepulley and connected at opposite ends to the rack bar and block, meansfor normally preventing rotation of the pinion, and means for rotatingthe pinion to raise or lower the rack bar.

2. A hoisting mechanism including a vertically movable rack bar, avertically movable block, a pinion carried by the block, meshing withthe rack bar, a pulley, a flexible member extended upward over thepulley and connected at opposite ends to the rack bar and block, a woringear rotatable with the pinion and a worm journaled upon the block andengaging the Worm gear.v

3. A hoisting mechanism including a vertically movable lifting bar, avertically movable block, a pulley, a flexible connection extendedupward over the pulley and connected at opposite ends to the block andlifting bar, and means upon the block for moving the lifting bar andblock in opposite directions.

4. A hoisting mechanism'including a vertical frame, a rack bar slidablymounted therein, a block slidably mounted in the frame, a pinion uponthe block meshing with the rack bar, a pulley upon the upper portion ofthe frame, a flexible member extended over the pulley and connected atopposite ends to the block and rack bar, gears rotatable with thepinion, oppositely disposed bearings upon the block, a worm shaftjournaled in each set of bearings, a worm upon each worm shaft meshingWith one of said gears, means operatively connecting the worm shafts,and means for rotating one of the worm shafts.

5. A hoisting mechanism including an upright frame, a rack barvertically slidable therein, a channel shaped block vertically slidablein the frame, the teeth of the rack bar extending into the channelthereof, a pinion within said channel block meshing with the rack bar, apair of pulleys upon opposite sides of the upper portion of the frame, aiexible member extended over each pulley and connected to the block andrack bar at opposite ends, a pair of worm wheels rotatable with thepinion and located upon opposite sides of the frame, spaced ears uponopposite .sides of the block, a pair of worm shafts journaled in saidears, a worm upon each. shaft meshing with one of the worm gears,pinions at the outer ends of the worm shafts, an idler upon the framemeshing with said pinions, and a flat sided shank upon one of the wormshafts for -receiving a tool torotate the same.

In testimony that I claim the above, I have hereunto subscribed my name.

JOHN A. MORRISON.

